Small line size vortex flowmeter

Abstract

A vortex flowmeter and method includes a conduit for process fluid flow and a shedder disposed within the central bore of the conduit. First and second diaphragms are mounted in inner wall portions of the conduit, on opposite sides of the shedder. A sensor is disposed externally to the conduit, and is coupled to each diaphragm with fill tubes. The diaphragms respond to pressure variations generated by vortex shedding, and transmit pulse trains through the fill tubes to a sensor. The pulse trains, which are substantially out of phase with one another, are effectively synchronized with one another by reversing phase of one pulse train.

1. A sanitary vortex flowmeter comprising:
 a conduit for process fluid flow, said conduit having one or more inner walls defining a central bore; 
 a shedder disposed within said central bore; 
 first and second diaphragms embedded in opposite inner wall portions of the conduit, adjacent to the shedder; 
 a sensor disposed externally to said conduit; 
 a first fill tube containing fill fluid, configured for communicably coupling said first diaphragm to said sensor; 
 a second fill tube containing fill fluid, configured for communicably coupling said second diaphragm to said sensor; 
 a first diaphragm holder configured to maintain the first diaphragm in said embedded position on said conduit; and 
 a second diaphragm holder configured to maintain the second diaphragm in said embedded position on said conduit. 
 
     
     
       2. A vortex flowmeter comprising:
 a conduit for process fluid flow in a downstream direction therethrough, said conduit having one or more inner wall portions defining a central bore; 
 a shedder disposed within the central bore; 
 a diaphragm embedded in an inner wall portion of said conduit, adjacent to the shedder; 
 a sensor disposed remotely from said conduit; and 
 a coupling configured to communicably couple said sensor to said diaphragm. 
 
     
     
       3. The flowmeter of  claim 2 , wherein said sensor is configured to detect pressure variations within the fill fluid. 
     
     
       4. The flowmeter of  claim 2 , comprising:
 an additional diaphragm embedded in another inner wall portion of said conduit, wherein said diaphragm and said additional diaphragm are disposed on opposite sides of the shedder from one another; 
 an additional coupling configured for communicably coupling said additional diaphragm to a sensor. 
 
     
     
       5. The flowmeter of  claim 4 , wherein said coupling and said additional coupling each comprise a fill tube containing a fill fluid, each of said fill tubes being configured for communicably coupling said diaphragm, via the fill fluid, to said sensor. 
     
     
       6. The flowmeter of  claim 4 , wherein said coupling and said additional coupling each comprise a non-fluidic mechanical linkage, each of said linkages being configured for communicably coupling said diaphragm, via the linkage, to said sensor. 
     
     
       7. The flowmeter of  claim 2 , wherein said sensor is coupled to a transmitter. 
     
     
       8. The flowmeter of  claim 4 , wherein:
 a first diaphragm holder is configured to maintain said diaphragm in said embedded position on an inner wall portion of the conduit; and 
 a second diaphragm holder is configured to maintain said additional diaphragm in said embedded position on an other inner wall portion of the conduit. 
 
     
     
       9. The flowmeter of  claim 8 , wherein said diaphragm and said additional diaphragm are respectively removable from said first and second diaphragm holders. 
     
     
       10. The flowmeter of  claim 8 , wherein said first and second diaphragm holders are each removably fastened to said conduit. 
     
     
       11. The flowmeter of  claim 8 , wherein said first and second diaphragm holders are integral with the inner conduit wall. 
     
     
       12. The flowmeter of  claim 8 , wherein said first diaphragm holder is configured to couple said diaphragm to said coupling. 
     
     
       13. The flowmeter of  claim 12 , wherein said second diaphragm holder is configured to couple said additional diaphragm to said additional coupling. 
     
     
       14. The flowmeter of  claim 13 , comprising a sensor holder configured to communicably couple said couplings to said sensor. 
     
     
       15. The flowmeter of  claim 13 , comprising a second sensor. 
     
     
       16. The flowmeter of  claim 13 , wherein said sensor is configured to detect pressure pulse trains within the couplings. 
     
     
       17. The flowmeter of  claim 13 , wherein said diaphragm and said additional diaphragm are configured to respectively impart the pulse trains to said coupling and said additional coupling, said pulse trains being respectively out of phase with one another. 
     
     
       18. The flowmeter of  claim 17 , further comprising a summation module configured to combine the pulse trains with one another. 
     
     
       19. The flowmeter of  claim 18 , wherein said summation module is configured to reverse the phase of one of the pulse trains relative to the other of the pulse trains. 
     
     
       20. The flowmeter of  claim 19 , wherein said coupling and said additional coupling are respectively communicably coupled to separate sensors. 
     
     
       21. The flowmeter of  claim 20 , wherein the summation module comprises a processor configured to receive pulse trains from a plurality of sensors. 
     
     
       22. The flowmeter of  claim 19 , wherein said coupling and said additional coupling are both communicably coupled to a single sensor. 
     
     
       23. The flowmeter of  claim 22 , wherein said summation module comprises a sensor holder configured to communicably couple said coupling and said additional coupling to opposite faces of a single sensor. 
     
     
       24. The flowmeter of  claim 23 , wherein said coupling and said additional coupling comprise first and second fill tubes, and said sensor holder is configured to communicably couple said first and second fill tubes to opposite faces of a single sensor. 
     
     
       25. The flowmeter of  claim 24 , wherein said sensor comprises a piezoelectric bimorph. 
     
     
       26. The flowmeter of  claim 2 , wherein said central bore has a transverse dimension of up to 2 inches (5 cm). 
     
     
       27. The flowmeter of  claim 26 , wherein said central bore has a transverse dimension ranging from at least about ¾ inch (1.9 cm) to about 1.5 inch (3.8 cm). 
     
     
       28. A method of producing a sanitary vortex flowmeter comprises:
 a) disposing a shedder within a central bore of a conduit for process fluid flow; 
 b) mounting a diaphragm in an inner wall of the conduit, adjacent to the shedder; 
 c) disposing at least one sensor externally to the conduit; and 
 d) disposing a coupling between the diaphragm and the sensor to communicably couple the diaphragm to the sensor. 
 
     
     
       29. The method of  claim 28 , further comprising (e) mounting an additional diaphragm in an inner wall of the conduit, opposite from the diaphragm, and adjacent to the shedder. 
     
     
       30. The method of  claim 29 , further comprising (f) disposing an additional coupling between the additional diaphragm and the sensor to communicably couple the additional diaphragm to the sensor. 
     
     
       31. The method of  claim 30 , wherein said disposing (d) and said disposing (f) further comprise disposing couplings in the form of fill tubes containing fill fluid between the diaphragms and the sensor. 
     
     
       32. The method of  claim 31 , wherein said mounting (b) and said mounting (e) further comprise configuring the diaphragms to respectively impart pulse trains to said first and second fill tubes. 
     
     
       33. The method of  claim 32 , comprising configuring a summation module configured to combine the pulse trains with one another. 
     
     
       34. The method of  claim 33 , comprising configuring the summation module to reverse the phase of one of the pulse trains relative to the other of the pulse trains. 
     
     
       35. The method of  claim 34 , comprising communicably coupling said first and second fill tubes to opposite faces of said sensor. 
     
     
       36. The method of  claim 35 , comprising communicably coupling said sensor to a transmitter. 
     
     
       37. The method of  claim 28 , wherein said mounting (a) comprises mounting said first diaphragm in a first diaphragm holder, mounting said second diaphragm in a second diaphragm holder, and disposing said first and second diaphragm holders on the conduit.